The present invention relates to a method and apparatus for no-till planting. More particularly, the present invention relates to an improved no-till planter attachment configured to improve seed germination, to provide better plant vigor, and to establish a higher plant stand to promote early-season plant growth.
The goal of most farmers is to complete corn planting as early in the planting season as possible in order to maximize yield potential for corn. For many years, farmers relied upon deep tilling methods using a moldboard plow, a chisel plow, or other apparatus to cut deeply into the soil and bury any residue from a previously planted crop remaining after a harvest. After such primary deep tilling operation, a secondary tilling operation using a plurality of disks or sweeps are used to break up large clumps of tilled soil.
One problem associated with conventional deep tilling methods is the wear and tear on tractors used to pull the deep tilling apparatus. In addition, fuel costs for pulling deep tilling apparatus and for the required multiple passes over the same field are high. Conventional deep tilling methods also contribute to erosion of the cultivated fields by water run off and wind. This erosion problem was addressed in the 1985 farm bill which includes regulations for farming highly erodible land (HEL). Growers that farm HEL must be in compliance with the farm bill regulations by 1994. All farm plans with HEL must have at least 30% residue cover after planting each spring. Farmers must stay in compliance with the farm bill in order to maintain eligibility for USDA subsidy payments.
Over the past several years the concept of no-till or low-till farming has developed. In no-till or low-till farming, fields are not plowed or cultivated between crops. Attachments on the planter open a furrow, deposit seeds therein, and close the furrow in a single pass operation.
Several types of row cleaner devices have been developed to clean residue remaining from a previous crop from an area in front of each planter row as the planter unit is pulled through the field. See, for example, U.S. Pat. No. 4,785,890 to Martin; U.S. Pat. No. 5,076,180 to Schneider; and U.S. Pat. No. 5,129,282 to Bassett et al. These row cleaners typically include a pair of rotating wheels or brushes coupled to the planter unit in front of each row to move residue out of a planter row ahead of a planter unit. Therefore, the row cleaners provide substantially bare, untilled soil in which the planter unit can plant seed.
The apparatus method of the present invention does not clean away the residue from each planter row like the conventional row cleaners discussed above. In fact, the apparatus of the present invention functions in an opposite manner by intentionally moving a mixture of soil and previous crop residue into each planter row. Advantageously, the present apparatus and method of the present invention mixes the remaining residue with soil in an area ahead of each planted row. The mixing of soil and residue in the present invention is shallow mixing which occurs only in a confined area and which does not disturb the soil immediately under the planter unit. There is no need for deep primary or secondary tillage with the apparatus and method of the present invention.
The apparatus of the present invention uses a disk hiller to build up about a 1 inch to about a 11/2 inch deep elevated ridge above a top surface of the soil in front of the planter unit. The first and second blades of the disk hiller of the present invention are positioned at an angle relative to each other which is opposite from the angle of the wheels or brushes of the row cleaner devices discussed above so that the disk hiller forms the elevated ridge as the planter unit moves. The disks penetrate the soil on either side of the planted row area approximately 3/4 inch deep and cut a 3-4 inch soil width.
The double disk apparatus of the present invention is used in a very reduced or no-tillage farming operation which reduces fuel and labor costs by as much as 60-70% as compared to current practices. The elevated ridge formed by the disk hiller elevates the planter unit slightly above the top surface of the soil. This elevated ridge therefore allows the seeds to be planted at a normal depth by the planter unit, usually about 13/4 inches to about 21/2 inches deep, but the seeds are raised up in the soil profile toward the top surface of the soil since the planter unit rides on the elevated ridge.
The apparatus of the present invention evenly mixes the soil and residue which can result in higher percent residue cover. The result is a more even residue cover than if it had been left as no-till. Row cleaning units such as disclosed in the Martin patent reduce the amount of residue cover. The row cleaner units concentrate the residue in area between the planted rows. The disk mixing action of the present invention evenly blends crop residue and soil then places the mixture back in the area of origination. The result from the mixed soil and crop residue is a more even distribution of the residue.
One problem associated with conventional no-till farming methods is slow plant growth early in the season. Typical no-till attachments include a coulter mounted directly in front of each row of the planter. Such coulters can either cause "sidewall" compaction and/or create air pockets, both of which reduce seed germination and seedling growth, especially in cool, wet conditions which are normal during optimum planting dates.
Advantageously, the apparatus of the present invention can be used earlier in the planting season than conventional row cleaner devices. The double disk apparatus of the present invention requires only the top 1 inch to 11/2 inches of the soil to be ready to plant. The soil dries and warms up from the top surface in a downward direction. Typical planting time occurs in April in the central corn belt. Soil temperatures in the worked area are often a minimum of 6.degree. F. higher per inch as you move upwardly in the soil profile. For example you could have a temperature at 21/2 inches below the top surface of 48.degree., and a temperature 1 inch higher of about 54.degree.. Such higher temperatures would enhance early season growth of the corn. In the present invention, the seeds are planted about 1 inch to about 11/2 inches closer to the top of the "original" soil surface of the soil than conventional planting operations. Therefore, the seed planting position is higher in the soil profile, but still in an undisturbed or untilled soil profile. Seed placement underneath the elevated ridge is in a warmer and drier area than seeds planted at the typical deeper location in the soil profile. This improves the rate of seed germination and improves the growth of the corn early in the season.
The soil in the ridged and upper soil surface is warmer, drier, and more friable than soil farther down in the soil profile. Soil that is more friable allows seeds to have good contact with the soil surrounding the whole seed. Partial attachment of the soil seed contact may result in lower germination and may cause the seed to dry out. This reduces seedling growth and vigor early in the season and often results in lower plant populations. Subsequently corn yield is reduced at harvest. Friable soil at the surface allows the sealing wheels at the back side of the planter to close off the furrow or slot and thereby prevent the soil below the slot area where the seed is planted from drying out.
The apparatus of the present invention also improves water drainage to keep the soil in the planted row moist, but not water logged. The firming action of the gauge wheels of the planter moving over the elevated ridge is an important aspect of the present invention. Water soaks into the elevated ridge instead of eroding the soil away. Water is channeled down either side, but not to the extent that any substantial eroding occurs.
No-till farming increases earthworm population. Earthworms come up to the surface of the soil for feeding and build a small mound areas (midden) by pulling in residue and mixing it in with soil. The crop residue material is a food source and keeps the earthworm channel below open and the moisture high (relative humidity). One aspect of this is that the earthworm middens, surface mound of a earthworm channel, makes the surface area rough to plant crops. By running the double disk units in front of the row, the result would be a smooth area to operate the planter units and a more even distribution of crop residue over the soil surface.
The use of disk hillers in certain types of farm equipment is known. See, for example, U.S. Pat. No. 4,762,181 to Cox and U.S. Pat. No. 3,372,657 to Hansen. The Cox patent discloses a pull type implement which includes a coulter to cut residue and a deep chisel shank to till the soil deeply below the surface. Because of the deep soil shank, the Cox patent discloses a disk hiller located behind the shank to fill in the trenched area formed by the shank. The Cox patent uses a deep tillage operation, and the Cox patent is not concerned with minimizing or providing very little disturbance of the soil like the apparatus and method of the present invention. The Hansen patent also discloses a plow for providing deep tillage of the soil.
According to one aspect of the present invention, a no-till apparatus is provided for use with a planter unit which plants seeds as the planter unit is pulled along a predetermined path. The planter unit includes means for cutting a furrow at a predetermined depth and means for depositing seeds in the furrow. The apparatus includes means for forming an elevated ridge including a mixture of soil and residue remaining from a previous crop without cutting the soil at a depth greater the predetermined depth, and means for coupling the elevated ridge forming means directly to the planter unit so that the elevated ridge forming means forms the elevated ridge ahead of and aligned with the planter unit so that the planter unit plants seeds at substantially the predetermined depth below a top surface of the elevated ridge.
In the illustrated embodiment, the means for forming an elevated ridge includes a disk hiller having a first blade and a second blade spaced apart from the first blade. The first blade and the second blade are aligned at an angle relative to each other to form the elevated ridge.
Also in the illustrated embodiment, the coupling means is configured to position a trailing edge of the first and second blades a predetermined distance ranging from about 4 inches to about 8 inches ahead of the planter unit. Preferably, the predetermined distance is about 6 inches.
Illustratively, a leading edge of the first blade of the disk hiller is spaced apart from a leading edge of the second blade by a distance ranging from about 8 inches to about 16 inches. A trailing edge of the first blade is spaced apart from a trailing edge of the second blade by a distance ranging from about 4 inches to about 8 inches. Preferably, the leading edge of the first blade is spaced apart from the leading edge of the second blade by a distance of about 13 inches, and the trailing edge of the first blade is spaced apart from the trailing edge of the second blade by a distance of about 6 inches. The first and second blades of the disk hiller are illustratively aligned at about a 15.degree. angle relative to an axis of symmetry of the disk hiller.
The planter unit includes a double disk opener for cutting a furrow in the ground at a predetermined depth, means for depositing seeds in the furrow, and a pair of gauge wheels. The top surface of elevated ridge formed by the disk hiller is located about 1 inch to about 11/2 inches above a top surface of the soil. The pair of gauge wheels of the planter unit ride on the elevated ridge formed by the disk hiller to provide a raised profile seeding depth for the planted seeds relative to a top surface of the soil. The first and second blades of the disk hiller cut into the top surface of the soil only to a depth less than said predetermined depth of the double disk opener.
According to another aspect of the present invention, an improved no-till farming method is provided for preparing soil covered with a residue from a previous crop for planting seeds using a planter unit. The planter unit includes a double disk opener for cutting a furrow in the soil at a predetermined depth and means for depositing seeds in the furrow. The method includes the step of forming an elevated ridge including of a mixture of soil and residue ahead of the planter unit by cutting below a top surface of the soil at a depth less than said predetermined depth to mix soil and residue in front of the planter unit so that the planter unit plants seeds below a top surface of the elevated ridge to provide a raised profile seeding depth for the planted seeds relative to the top surface of the soil.
Additional objects, features, and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of a preferred embodiment exemplifying the best mode of carrying out the invention as presently perceived.